Improve Synapse reverse-proxying Apache examples

Thanks to @ralfi!

examples/apache/matrix-synapse.conf

@@ -40,8 +40,9 @@
 	ProxyPassMatch ^/_matrix/client/r0/user_directory/search !
 
 	# Proxy all remaining traffic to Synapse
-	ProxyPass / http://127.0.0.1:8008/
+	AllowEncodedSlashes NoDecode
-	ProxyPassReverse / http://127.0.0.1:8008/
+	ProxyPass /_matrix http://127.0.0.1:8008/_matrix retry=0 nocanon
+	ProxyPassReverse /_matrix http://127.0.0.1:8008/_matrix
 
 	# Map /.well-known/matrix/client for client discovery
 	Alias /.well-known/matrix/client /matrix/static-files/.well-known/matrix/client
@@ -111,8 +112,9 @@
 	# Proxy all remaining traffic to the Synapse port
 	# Beware: In this example the local traffic goes to the local synapse server at 127.0.0.1
 	# Of course you can use another IPADRESS in case of using other synapse servers in your network
-	ProxyPass / http://127.0.0.1:8048/
+	AllowEncodedSlashes NoDecode
-	ProxyPassReverse / http://127.0.0.1:8048/
+	ProxyPass /_matrix http://127.0.0.1:8048/_matrix
+	ProxyPassReverse /_matrix http://127.0.0.1:8048/_matrix
 
 	ErrorLog ${APACHE_LOG_DIR}/matrix.DOMAIN-error.log
 	CustomLog ${APACHE_LOG_DIR}/matrix.DOMAIN-access.log combined